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Effect of slurry dilution, structural carbohydrates, and exogenous archaea supply on in vitro anaerobe fermentation and methanogens population of swine slurry
Author(s) -
Morazán Henris,
Seradj Ahmad Reza,
AlvarezRodriguez Javier,
Abecia Leticia,
Babot Daniel,
YañezRuiz David R.,
Balcells Joaquim
Publication year - 2015
Publication title -
environmental progress and sustainable energy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.495
H-Index - 66
eISSN - 1944-7450
pISSN - 1944-7442
DOI - 10.1002/ep.11952
Subject(s) - population , food science , bacteria , temperature gradient gel electrophoresis , incubation , biology , fermentation , microorganism , archaea , chemistry , microbiology and biotechnology , 16s ribosomal rna , biochemistry , genetics , demography , sociology
Artificial slurry (4% dry matter) was prepared using fresh feces and urine obtained from four pregnant sows fed with commercial diet. Freeze‐dried dairy cattle feces were used (external archaea) as co‐inoculum (Co‐i) and structural carbohydrates (CHO: apple pulp; sugar beet pulp; and wheat straw) as substrates. Bottles were incubated (39 ± 1°C for 56 days), and the gas production was measured (mbar) and converted to the volume. A sample of produced gas was taken and analyzed for methane concentration using a gas chromatography. Bottles were opened at days 0, 25, and 56 to determine total bacteria, total, and hydrogenotrophic methanogens archaea (HMA) concentrations using quantitative polymerase chain reaction and population biodiversity using denaturing gradient gel electrophoresis (DGGE). Incubation time reduced the titers of total bacteria and archaea (P < 0.01) but did not modify HMA population. Doses of Co‐i showed a positive correlation with HMA titers, although interacted with an incubation period (P < 0.001); at 5% Co‐inoculation, total bacteria decreased significantly (0–25 days) but remained steady until day 56 (P > 0.05), whereas at 10% Co inoculation, titers decreased constantly. Most of the archaeal DGGE bands were observed in all samples, suggesting a common microbial population origin but Co‐i supply altered the DGGE structure of archaea populations. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 54–64, 2015